1. Field of the Invention
The present invention relates to a method for processing input from a touch input device such as a tablet or the like used as an input device, and an input control apparatus for implementing the method.
2. Description of the Related Art
Portable information processing apparatuses, which are becoming popular, utilize touch input devices such as tablets or digitizers as input devices instead of mice. Generally, a tablet or digitizer is integrated with a display such as a liquid crystal display by being mounted as a transparent plate over the display or placed underneath the display, and is configured to detect the position of a stylus pen or the like on the display when the stylus pen or the like, as a pointing device, contacts the display screen.
Such input devices, generally called touch screens or touch panels, have been implemented in various ways, including one that uses a resistive film (pressure sensitive tablet) consisting of transparent electrodes bonded to the surface of a display (CRT, LCD, plasma display, etc.) and performs an input operation by touching the screen with a finger or a pen, and one that performs an input operation on the screen with the digitizer, mounted underneath the display, detecting the position of the input by detecting the magnetism being generated at the tip of the pen (when the pen is touched to the screen, magnetism is generated, and the position of the input is detected by the electromagnetic induction type digitizer mounted underneath the display). In addition to such pressure sensitive tablet and electromagnetic induction digitizer methods, various methods of input position detection have been implemented, such as an ultrasonic surface acoustic wave touch panel method that uses ultrasonic waves.
A tablet, like a mouse, is also used to specify a position in a graphical input operation, select a menu or activate a software program by manipulating an icon, and so on.
A mouse contains mouse buttons, and a mouse operation to press and release a mouse button is called a mouse click, the mouse operation being classified as a single click, double click, etc. according to how many times the button is pressed in succession. By putting the mouse cursor on a designated icon and clicking the mouse on it, desired processing can be specified. In the case of a pen operation on a tablet, if an operation to touch the pen or the like to the tablet (called a pen down motion) and then lift it off the tablet (called a pen up motion) is called a tap, then moving the mouse cursor and single-clicking or double-clicking the mouse corresponds to performing a single tap or double tap on a designated icon. The pen down and pen up motions here embrace operations performed not only by a pen but also by a finger or the like.
In a graphical input operation, when a tablet 10 is touched with a pen 14, as shown in FIG. 1, a dot is drawn on a display 12 at the position of the touch. The figure shows the tablet 10 and display 12 as a single integral unit. When the pen 14 is moved by holding it touched to the tablet 10, a line corresponding to its movement is drawn on the display 12.
In the case of a mouse, there is a mouse operation, called drag, in which the mouse is moved while keeping the mouse button pressed down; in a graphical input operation, a line is drawn when the mouse is dragged. On the other hand, when the mouse is moved without holding down a mouse button, the mouse cursor merely moves on the display.
In the case of a graphical input operation by a pen on a tablet, on the other hand, if a dot or line were always drawn with a pen down motion, an operation to move the cursor without drawing a dot or line, such as the operation shown in FIG. 3, could not be accomplished. To avoid this, an operation mode is provided in which even when the pen is actually touched to the tablet, the motion is not interpreted as a pen down motion but the mouse cursor is merely caused to move. This mode is called a hovering mode. To switch the operation between normal mode and hovering mode, a normal mode selection button 16 and a hovering mode selection button 18 are provided outside the display screen, as shown in FIG. 4. In an icon manipulation in the hovering mode, a pen tap on an icon only results in positioning the cursor on that icon.
In this way, an input operation on a touch input device such as a tablet or digitizer has required mode switching using the buttons provided outside the screen, and in the case of an input operation that requires frequent mode switching, the operation has been very tiring and inefficient for an operator.